... The reports contain no evidence that any aides to former Democratic President Barack Obama acted improperly, the sources said, but they do indicate some Trump associates may have violated an obscure 1799 law, the Logan Act, which prohibits unauthorized U.S. citizens from negotiating with a foreign government that has a dispute with the United States ...https://www.yahoo.com/news/republic...p-russia-probes-could-backfire-162911865.html

Trump team forced for first time to hand over documents to Mueller's Russia investigationAndrew BuncombeThe IndependentSeptember 12, 2017

... He asked it to preserve evidence relating to former general Michael Flynn, who was forced to resign as Mr Trump’s national security adviser, as well as to a June 2016 meeting between a Kremlin-linked Russian lawyer and the President’s eldest son, son-in-law and campaign manager ...